I'm an amateur astronomer and an amateur telescope maker. I've also been into photography since the 1960's. As a telescope maker I also grind, polish, and figure my own telescope mirrors.

Testing during the mirror figuring process is crucial to make a good mirror. One of the best testing procedures is called the Foucault Test using a Couder mask. ( Do a little Googling for info on this. ) The main problem of this test is that it can be quite subjective since it depends upon the human eye to determine if 2 areas are the same shade of gray. I found some Windows based software that creates a virtual Couder mask over a live video image of the mirror captured by a webcam and then compares the histogram of each zone side by side allowing me to adjust the tester until both histograms are the same. Great software!!!

But webcams suck as far as image quality goes because no webcam has an optical zoom lens, which is needed to get a decent size image on the monitor. So I am looking for a small digital camera that has the capability and software to put a live image on my laptop's screen. ( Lenovo T61, Win7 64bit )

I have been searching the web to find info on a camera that will do this. But different manufacturers call this feature different names. I emailed Canon with my question and got a response right away but it seems that only their new dslr's support it. Some of their older PowerShots did, but not all and I have no clue as to which ones. I have emailed Nikon and Panasonic but have not received replies.

So I'm asking the question here in hopes that some of you can point me in the right direction.

You might want to check out the various versions of PSRemote from Breeze Systems (link). Support for remote shooting with P&S cameras has been discontinued by Canon but if you can pick up one of the cameras on this list at the right price then that might be an alternative to buying a DSLR.

Thanks for the links Bob. I'm keeping my eye on a few Canon Powershots on eBay. But other manufacturers must have cameras that are capable of digital video out via USB. Know of any? And I guess what amazes me is that I can't find a single webcam with optical zoom, which is really all I'm looking for and hence the search for a Point & Shoot with the capability.